One of the lies commonly related by climate change deniers is that in the 1970s, most scientific papers predicted the climate would cool and there would be a new ice age. Indeed, the most cited examples of this are articles in Time in 1974 and Newsweek in 1975, both of which stated that a cooling trend may lead to a decrease in food production. However, these are news magazines, not part of the scientific literature. A survey of the real literature at about that time shows that from 1965 onwards, the number of papers predicting global warming far outstripped the number predicting cooling1, to the tune of a ratio of about 6 to 1. So, the climate deniers are lying, again.
Another lie attributed to climate scientists and others by deniers is that they are exaggerating the rate of sea-level rise. This has been shown to be yet another lie by the collection of both tide-gauge data and satellite altimetry2. One of the ways deniers tend to misinterpret data is by only looking at short intervals of time. For instance, they look at a brief interval in the sawtooth record of sea-level2, or temperature3, and interpret it as supporting their ‘view’ and accuse climate scientists of hiding the facts. The classic example of this was the ‘end of sea-level rise’ in 2006, which at the time was a small short-term blip which could only be interpreted as a cessation of the rise if you ignored the short term variability in the previous parts of the record. Of course, sea-level has resumed its inexorable rise subsequent to the deniers’ interpreted cessation. Deniers don’t tend to use this furphy any more.
Climate change deniers will often say that climate scientists deny the existence of the Medieval Warm Period (MWP), but this is just another of their numerous lies. The MWP was a period of relatively warm climate in the North Atlantic and lasted from about 950 to 1250, and its existence was determined by climate scientists and archaeologists. Climate change deniers look at the average global temperature estimates for this interval and whine that it doesn’t show the warm period. However, this warming was restricted to the North Atlantic; other parts of the planet, for instance, the tropical Pacific, were colder. The interval is shown in the Northern Hemisphere temperature reconstructions, as being about 0.4 degrees warmer than the preceding several hundred years. After the medieval warm period the temperature dropped significantly (~0.6 degrees) into what is called the ‘little ice age’, which was at its peak in the 1600s and 1700s. These variations pale into insignificance compared to the rise in temperature in the last 50 years, where it has risen by over 1.0 degree. Climate change deniers also used the lack of a mechanism for the medieval warm period to cast aspersions on climate science. However, that was put to bed in 2009, when it was discovered that the cause was a strong positive North Atlantic Oscillation, which lasted for the period covered by the MWP.
Attributing such lies to climate scientists is a stupid thing for climate change deniers to do. That is because the science is backed up by data, something that is anathema to your average climate change denier.